Clint Barmes

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The Pittsburgh Pirates were cautiously optimistic about their chances heading into last season, and with free-agent infielder Clint Barmes signed to a multi-year deal, that was one spot they thought they could count on.

However, Barmes was largely a disappointment in a Pirates uniform last year, batting only .229 with his strikeout numbers on the rise and his on-base percentage heading in the other direction.

His average has climbed a bit in spring training, but with an on-base percentage still well below .300, Barmes has plenty to do in proving that he should be a regular part of the Pirates' lineup.

Melky Cabrera

Leading into the end of last summer, it looked like Melky Cabrera could be an MVP candidate for the San Francisco Giants and, in turn, work his way into a huge contract this offseason.

But that all changed when he was handed a 50-game suspension in August after testing positive for a performance-enhancing supplement.

He's got plenty to prove as he looks to show everyone in baseball that his superb season wasn't due to the supplements, but if the pressure gets to be too much, Cabrera could very well fall short of the output he showed in 2012.

Pedro Florimon

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The most glaring hole in the Minnesota Twins roster in 2012 was no doubt in their starting rotation, but the middle infield positions were just as iffy, with a number of lackluster players rotating through the ranks.

Pedro Florimon caught on somewhat as the team's shortstop toward the end of the season and appears to be heading into the start of this season as a starter.

He batted only .219 last season with seven errors in 43 games, and with his performance not looking much better this spring, he'll be on a short leash as a number of viable infield prospects seem prepped to make the leap to the big leagues.

Jeremy Guthrie

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The Kansas City Royals' starting rotation will, no doubt, take on a different look in 2013 with James Shields and Wade Davis coming over in a trade from Tampa Bay and Ervin Santana making his way over from the Angels.

Jeremy Guthrie will be part of the rotation as well—though he's struggled to become the consistent pitcher that many thought he could become—and if he isn't able to provide the punch in the rotation that the organization is expecting, he could be on the move again.

Matt Garza

Over the past couple of seasons, there has been no shortage of trade talk involving Matt Garza and whether or not he'd be leaving the Chicago Cubs.

He wasn't moved last season prior to going down for the season in July, and with questions surrounding his health continuing to linger into the offseason, he's still in limbo.

Garza still isn't ready to throw off a mound and will certainly miss some time this season. If he can't prove that he can stay on the mound, at some point, he'll lose out on any leverage he could have this offseason once he hits the free agent market.

Chris Capuano

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The Los Angeles Dodgers have made so many additions to their roster over the past year that it's almost hard to believe they haven't made more subtractions.

Chris Capuano was brought in to add depth to the rotation a year ago, but with the big-name signings the team has made this offseason, it wouldn't be surprising to see the Cubs try to move Capuano, leaving him on the outside of a World Series' caliber roster.

John Buck

In bringing John Buck over from the Toronto Blue Jays this offseason, the New York Mets have a player who will undoubtedly be able to start at backstop from day one.

The question is how long he will be there.

The team also brought over highly touted catching prospect Travis d'Arnaud from Toronto. If Buck doesn't prove to be worthy of a starting job as the season gets underway, it could be a matter of time before he's replaced.